1. Field
Embodiments of the invention relate to electronic systems, and more particularly, to amplifiers.
2. Description of the Related Technology
An amplifier, such as an operational amplifier or an instrumentation amplifier, can include autozero and/or chopper circuitry for reducing the amplifier's input offset voltage.
In one example, an autozero amplifier can include a primary amplifier, an auxiliary amplifier, and a capacitor, and the auxiliary amplifier can operate during an autozero phase to store a voltage across the capacitor to correct for the input offset voltage of the primary amplifier. In another example, a chopper amplifier includes input chopping switches that can be used to chop or modulate the amplifier's input signal during an input chopping operation, thereby up-shifting the frequency of the amplifier's input signal. Additionally, the chopper amplifier can include a filter for filtering the amplifier's input offset voltage, which can be separated in frequency from the chopped input signal. The chopper amplifier can further include output chopping switches for demodulating or down-shifting the frequency of the chopped input signal during an output chopping operation.
Although including autozero and/or chopper circuitry in an amplifier can reduce the amplifier's input offset voltage, the autozero and/or chopper circuitry can also impact operational performance of the amplifier, such as by generating output glitches and/or noise.